JPS6125779Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a hearing protector, and more specifically, a hearing protector that can absorb only noise at a desired frequency and allow sounds other than those frequencies to pass through and be heard. Pertains to.

Conventionally, various types of hearing protection equipment such as so-called earplugs (hereinafter simply referred to as earplugs) have been used. The structure is designed to block the sound of

That is, conventional earplugs and the like are often made of cotton or soft plastic material, and are often structured to reduce or insulate external noise or sound when it reaches the cotton or the like. However, even if it is possible to achieve a noise isolation effect with earplugs, etc., all sounds are blocked and the ear canal is completely blocked from the outside air, so sound isolation can actually put a mental pressure on the nerves. The current situation is that it often irritates people and limits their opportunities to use it. Furthermore,
When working in a noisy area, it is high frequency noises, that is, noises with a frequency of 1000 Hz or more that irritate the nerves, and although it is desired that there be a device that can effectively absorb this type of noise, no proposals have been made yet. The reality is that there is not.

The present invention aims to solve the above-mentioned drawbacks, and specifically proposes a hearing protector for ears, etc., which can absorb high-frequency noise and effectively protect the ear canal, etc., while allowing normal sounds to pass through. .

That is, the present invention provides a sound-absorbing and sound-insulating body in which a space layer is interposed between a porous plate in which powdered metal particles are sintered inside an enclosure whose part is inserted into an ear canal, etc., and a sound insulating plate. It is characterized by being attached with.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

First, FIG. 1 is a longitudinal cross-sectional view of a protective equipment according to one embodiment of the present invention, and in FIG.
indicates a sound absorbing and sound insulating body (hereinafter referred to as sound absorbing body),
The sound absorber 1 and the like are attached to the inside of the enclosure 2 in a detachable or fixed manner. The enclosure 2 is usually made of synthetic resin, elastic rubber, etc., and in particular, one end 2a of the enclosure 2 is tapered so that the tapered part 2a can be inserted into an ear canal or the like during use. At this time, an introduction hole 3 is usually formed in the tip 2a along its axial center, so that, for example, sounds other than the frequencies that are absorbed after passing through the sound absorber 1 reach the inside of the ear through the introduction hole 3. .

Next, the sound absorbing body 1 is constructed by interposing an air layer between a porous plate made of sintered metal powder particles and a sound insulating plate, as shown in FIG. The structure is configured such that only sounds in high frequency ranges can be absorbed or insulated by adjustment.

That is, FIG. 2 is a cross-sectional view of an example of the structure of the sound absorber etc. 1, in which an air layer 6 is interposed between the sound insulating material 4 and the porous plate 5, and the sound from the direction of the arrow is resonates and the sound is absorbed. When using this sound absorber to pass frequencies of 100 to 1500 Hz, such as the conversational range, and muffle high frequencies, such as noise, the thickness of the porous plate 5 made of sintered metal powder particles or the thickness of the air layer 6 must be adjusted. adjust.

Incidentally, FIG. 3 is a graph showing the relationship between noise frequency and sound absorption coefficient for a sound absorber made of a porous plate 5 and a sound insulating material 4 with an air layer 6 interposed therebetween as shown in FIG. , A shows the case where the air layer 6 is 20 mm thick, B shows the case where the air layer 6 is 10 mm thick, and C shows the case where the air layer 6 is 40 mm thick. As is clear from FIG. 3, as the thickness of the air layer increases, the sound absorption region of the sound absorber etc. shifts to a low frequency region, and as the thickness of the air layer increases, it shifts to a high frequency region. Therefore, when absorbing only noise in the high frequency range, the thickness of the air layer is determined in accordance with an appropriate frequency that matches that frequency.

In addition, the porous plate is made of sintered metal material,
When forming a porous material by sintering a metal or the like, it is preferable to construct it as a sintered body of aluminum or its alloy powder, or a sintered body of copper or its alloy powder.

Next, examples will be described.

First, as shown in FIG. 4, two enclosures 2 were connected by a holder 7, and a sound absorber etc. 1 having the structure shown in FIG. 2 was attached inside each enclosure 2. In this case, the thickness L of the sound absorber 1 is 20 mm, the porous material 5 is a porous sintered aluminum material (thickness 3 mm), the sound insulation plate 4 is an aluminum plate with a thickness of 3 mm,
The thickness of the air layer 6 was 15 mm. In this case, conversational sounds were transmitted well, but high-frequency noise could be muffled.

As explained in detail above, the present invention provides a sound absorbing body with an air layer interposed between a porous plate made of sintered metal powder particles and a sound insulating plate inside an enclosure. etc. are configured to transmit sounds of 100 to 1500 Hz while muffling high frequency sounds. Therefore, for example, low frequency sounds such as conversation sounds can be easily heard through, whereas high frequency sounds such as noise can be easily muffled. Furthermore, the area to be muted can be selected as desired by adjusting the thickness, structure, etc. of the sound absorber.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a protective device according to an embodiment of the present invention, Fig. 2 is a sectional view of an example of a sound absorber, etc., and Fig. 3 shows an air layer between a porous plate and a shielding plate. A graph showing the relationship between the high frequency of noise and the sound absorption coefficient of an interposed sound absorber, etc., and FIG. 4 is a front view showing a cross section of a part of the protective equipment according to another embodiment of the present invention. . Code 1... Sound absorber etc., 2... Enclosing body, 2a...
Tapered part, 3...Introduction hole, 3a...Partition wall, 4...Sound insulating material, 5...Porous material, 6...Air layer, 7...Holder.

Claims (1)

[Scope of utility model claims] A sound absorbing and sound insulating body is installed with an air layer interposed between a porous plate made of sintered metal powder particles and a sound insulating plate inside an enclosure part of which is partially inserted into the ear canal. Characteristic protective equipment for hearing, etc.